Urinary iodine tests are important to assess the level of iodine in the body in order to make timely adjustments. Urinary iodine level can indicate the presence of diseases such as hyperthyroidism or endemic goiter, in which case dietary adjustments or medication can be made early to prevent the disease from continuing to progress. Iodine is an important element in the synthesis of thyroid hormones. If there is too much iodine in the body, it may cause diseases such as hyperthyroidism, goiter, autoimmune thyroiditis and thyroid tumors. If there is too little iodine in the body, it may cause endemic goiter, hypothyroidism, etc. In children, it also affects the growth and development of bones, muscles, nerves, and the reproductive system. In pregnant women, too little iodine can also affect the development of the fetus’s nerves and bones. Therefore, it is necessary to check the urine iodine level, and if there is any abnormality in urine iodine, it is recommended to consult a doctor in time.